Mandrel-swing for bending-dies.



No. 794.390. PATENTBD JULY 11, 1905.

' J. J. BOAX.

MANDREL SWING FOR BENDING DIES.

APPLICATION FILED Fm. 1904.

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Win/ s s55 Arron/"5w No. 794.390. PATENTED JULY 11, 1905.

J. J. BOAX.

MANDREL SWING FOR BENDING DIES.

APPLICATION FILED P234. 1904.

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Arronnzm' 'UNITED STATES Patented July 11, 1905.

PATENT, OFFICE.

JOHN J. BOAX, OF MoKEESPORT, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEWV JERSEY.

I MANDREL-SWING FOR BENDlNG-DIES.

SPECIFICATION forming part of Letters Patent No. 794,390, dated July 11, 1905.

Application filed February 4, 1904. Serial No. 192,033.

To all whom, it may concern.-

Be it known that I, JOHN J. BOAX, a resident of McKeesport, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Mandrel-Swings for Bending-Dies; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to dies for bending tube-plates into skelp, and more especially to the means for supporting and handling the mandrel.

The object of my invention is to provide mechanism whereby the mandrel can be easily and positively swung into and out of operative position.

In the manufacture of tubing, and more especially lap-weld tubing, it is customary to bend the flat plate into practically tubular form, known as skelp, forsubsequent heating and welding. One way of bending the plate into skelp is by drawing the same through a flaring or bell-shaped die and over a mandrel cooperating therewith, the plate being drawn by means of a tongs or other gripper attached to a traveling chain or similar pulling mechanism. In order to permit the attachment of the tongs or gripper to the plate, it is necessary to swing the mandrel up out of the die and afterward to swing the same down upon the plate and into the die. It has been customary to handle the mandrel by means of a suspending chain or the like passing over an overhead sheave and manually pulling on the opposite end of the chain to raise and lower the mandrel. As the mandrel, especiallyfor large-sized plates, is of considerable weight, this is very hard work and severe on the workmen, besides resulting in loss of time.

The object of my invention is to provide power mechanism for raising and lowering these mandrels, whereby theymaybe quickly and easily swung into and out of place, thus doing away with the severe work and loss of time heretofore encountered and also more accurately positioning the mandrel than has heretofore been possible.

To this end the invention consists, generally stated, in suspending the mandrel by means of a link or the like from an overhead oscillating lever and actuating said lever by suitable power mechanism, preferably a power-cylinder, trunnioned or otherwise pivoted so as to vary its position with the position of the lever.

In the accompanying drawings, Figurc'l is a side elevation of a bending mechanism, showing my invention applied thereto. Fig. 2 is a side view, on an enlarged scale, of the die, mandrel, and mandrel-operating mechanism. Fig. 3 is a plan view of the same, partly in section; and Fig. 4 is afront elevation of the same.

The bending mechanism may be of the usual form and comprises a table or bench 1, either stationary or laterally movable, as is now the practice. This table is provided with traveling pulling means, preferably an end less chain 3, passing over an idle sprocketwheel 5 at the forward end of the table and over a driven sprocket-wheel at the rear end of the table and having its lower reach supported by suitable guide-wheels 7. The rear sprocket-wheel will be driven by any suitable mechanism, such as a motor mounted on said table, as is now the practice. On the forward end of the table is mounted the die 10, which may be of the usual type, being of flaring modified bell shape, having the forward flared portion open at the top, as shown. Cooperating with this die is the mandrel 11, which also is or may be of the usual form of mandrel for this purpose.

All of the parts so far described are or may be of the usual type and will be understood without further description, the particular forms shown having been selected for illustration merely.

My invention relates to mechanism for handling the mandrel 11. This mechanism comprises a lever 12, pivoted at 13 above the die 10, either in an overhead support or in standards 14, rising from the floor. The lever 12, preferably, is made in two parts, as shown in Figs. 3 and 4, although this is not essential. The mandrel is suspended from the forward end of this lever by means of a link 15, provided at its lower end with a fork pivoted to an extension 16 on the mandrel intermediate its ends and having its upper end pivoted between the forked forward end of the lever 12. The pivotal connections at both ends of the link yield freely, so that said link forms, in effect, a flexible connector for suspending the mandrel. As a consequence the latter will swing freely into and out of the die and when suspended will be in approximately horizontal position, so that when lowered onto the plate it will be in roper position thereon and will rest for its fu 1 length on the plate, so as to be drawn thereby into the die. At its rear end the lever is provided with counterweights 18, which will be of sufficient weight to raise the mandrel and hold it in its elevated position. To lower the mandrel, positive mechanism is employed, preferably a power-cylinder 20, having its piston-rod 21 connected directly to the rear arm of the le ver 12. The power-cylinder will be suitably mounted in any position to permit it to act on the lever, preferably being supported on the standards 14. In order to permit the cylinder to accommodate its position to the changing position of .the lever 12, said cylin der is pivotally supported on the standards 14, preferably by having trunnions 22 on opposite sides mounted in suitable bearings in said standards. One of these trunnions 22 is hollow and has connected thereto a pipe 23 for the admission of the pressure medium to the cylinder, this pipe being controlled by a suitable valve. Any pressure medium such as steam, water, or compressed air or gases-may be employed. This cylinder is of the single-acting type, and when pressure is admitted thereto it serves to push up on the rear end of the lever 12, thus raising the counterweights 18 and lowering themandrel 11 into posltion. When pressure is released from said cylinder, the counterweights return the piston to its normal position and raise the mandrel.

The mandrel will normally be held in the position shown in full lines, Fig. 2, and in this position the tongs 24 or other gripping device will be inserted through the die and attached to a plate, which is then drawn forward through the die. Pressure is admitted to the cylinder 20, thus causing the mandrel to be lowered as the tongs pass through the die, and said mandrel will descend in practically a vertical line until it rests upon the plate. The forward travel of the plate will then carry the mandrel with it and into the die until it assumes the dotted-line position shown in Fig. 2. Pressure will then be released from the power-cylinder 20; but the mandrel will be held in this position by the friction of the forwardly-traveling plate. As soon as the plate is pulled entirely through the die the mandrel will be relieved of the frictional pull, and the counterweights 18 will then automatically raise the mandrel, so that no loss of time will occur and the tongs or gripping device can be at once attached to a fresh plate and the foregoing operations repeated.

The mechanism described provides positive and simple means for handling the mandrel, thus doing away with the heavy work heretofore necessary for this purpose. Furthermore, the raising of the mandrel is accomplished automatically, so that no loss of time occurs, and when said mandrel is lowered the mechanism is such as to properly position the same on the tube-plate.

What I claim is 1. In a plate-bending device, the combination with the bending-die, of a cooperating mandrel, a suspending lever for said mandrel, flexible connections between the mandrel and lever, and power mechanism for oscillating said lever.

2. In a plate-bending device, the combination with a bending-die, of a cooperating mandrel, a suspending lever for said mandrel, flexible connections between the mandrel and lever, and a power-cylinder for oscillating said lever.

3. In a plate-bending device, the combination with the bending-die, of a cooperating mandrel, a pivoted lever, flexible means for suspending the mandrel from said lever, and reciprocating power mechanism connected directly to said lever and being pivotally mounted.

4. In a plate-bending device, the combination with a bending-die, of a cooperating mandrel, a pivotally-mounted lever, alink loosely pivoted to the forward end of said lever and to said mandrel, and counterweights on the rear end of said lever.

5. In a plate-bending device, the combin ation with the bending-die, of a cooperating mandrel, a pivoted lever, flexible means for suspending the mandrel from the forward end of said lever, counterbalancing means for said lever, and power mechanism connected to said lever and operating in opposition to said counterbalance.

6. In a plate-bending device, the combination with a bending-die, of a cooperating mandrel, flexible means for suspending said mandrel, automatically-operating means for adapted to raise said mandrel, and a pivotally 1o raising said mandrel, and mechanism for lowmounted power-cylinder connected to said ering said mandrel. lever and arranged to lower said mandrel.

7. In a plate-bending device, the combina- In testimony whereof I, the said JOHN J. tion with the bending-die, of a cooperating BOAX, have hereunto set my hand. I mandrel, an overhead pivoted lever, suspend- JOHN J. BOAX. ing means at the forward end of said lever Witnesses: and flexibly connected to the mandrel, a ROBERT C. TOTTEN,

counterweight on the rear end of said lever G. KREMER. 

